1. Field of the Invention
This invention relates to a high pressure fluid intensifier, such as an intensifier arranged to deliver a stream of fluid at very high pressure, to accomplish a function such as cutting, drilling or waterblast cleaning.
2. Description of the Prior Art
There are in the prior art various pressure intensifying systems where a larger working piston is reciprocated to provide a high pressure output by means of smaller high pressure pistons.
However, there are a number of interrelated problems connected with the shifting of the larger working piston at the end limit of travel of each of its strokes. To alleviate the possible interruption of the flow of high pressure output fluid during shifting of the working piston, it is desirable to accomplish this shifting as quickly as possible. One problem in the prior art is that of alleviating pressure surges in the working fluid while the working piston is being reversed. Also, to obtain a rapid reversal of the working piston, it usually requires a correspondingly rapid reversal in the flow of pressurized working fluid, which in turn further aggravates the problem of undesired pressure surges or hydraulic shocks in the system. One means of alleviating this is to provide one or more relatively large hydraulic accumulators to sustain the flow of output fluid during reversal of the working piston, while accomplishing the reversal of the working system at a somewhat slower rate. However, this usually adds considerably to the bulk and cost of the system.
Typical of the prior art devices which show pressure intensifying systems and various valve switching mechanisms adaptable for such systems are the following U.S. Patents: Atkinson, No. 153,296; West et al, No. 2,000,805; Rethmeier, No. 2,942,584; Murray, No. 3,045,611; Pennther, No. 3,540,349; Bowen, No. 3,565,191; McGann, No. 549,739; Maxwell No. 932,992; Bowser, No. 1,199,526, and Swiss Pat. No. 262891.
It is an object of the present invention to provide a high pressure fluid intensifier having a desirable balance of advantageous features, particularly with respect to the problems and considerations mentioned above.